Field of the Invention
The present invention relates to an imaging module configured so that a solid-state image sensing device is packaged on a three-dimensional wiring base, an insulating-tube-attached imaging module configured by using the imaging module, a lens-attached imaging module, and an endoscope.
Description of the Related Art
It is essential for an imaging module used in an endoscope to be small.
The imaging module is configured to include a small solid-state image sensing device such as a CCD (Charge Coupled Device) chip or a CMOS (Complementary Metal Oxide Semiconductor) chip and a wiring base that has a surface on which wirings are formed and is used to package the above-mentioned solid-state image sensing device thereonto.
In the above-described solid-state image sensing device, for example, stacked chips have a configuration in which terminals used to connect a wiring base to the opposite side of a light-receiving face via through-hole interconnections (TSV: Trough Silicon Via) are provided.
On the other hand, as the wiring base on which the solid-state image sensing device is mounted, for example, a three-dimensional wiring base is used.
The three-dimensional wiring base is used to three-dimensionally package electronic components thereon and has a structure in which wirings are formed on a surface of a three-dimensional molded product made of resin, ceramic, or the like.
For example, in an imaging module used in an endoscope, a three-dimensional wiring base is molded in a substantially cylindrical shape, and a circular mount surface is provided on a substantially cylindrical-shaped front end.
For example, imaging modules that are formed by use of the aforementioned solid-state image sensing device and the three-dimensional wiring base and are used in endoscopes, are disclosed in Japanese Unexamined Patent Application, First Publication No. 2001-27734, Japanese Unexamined Patent Application, First Publication No. 2009-201762, Japanese Unexamined Patent Application, First Publication No. 2011-240053, or Japanese Unexamined Patent Application, First Publication No. 2012-254176.
However, in the above-mentioned conventional technologies, the imaging module is covered with the cylindrical insulating tube in order to ensure electrical insulation between surface wirings formed on the three-dimensional wiring base; however, since the mount surface of the three-dimensional wiring base is formed in a circular shape, the entire outer-periphery of the mount surface is caught by the inner surface of the insulating tube at the time of inserting the imaging module into the insulating tube, there is a problem in that it is difficult to insert it into the insulating tube.
Additionally, in the above-mentioned conventional technologies, it is necessary to provide, on the surface of the mount surface, an alignment mark that serves as a mark used to package a solid-state image sensing device on the right position; however, since the mount surface of a three-dimensional wiring base used in an imaging module of an endoscope is extremely small, it is extremely difficult to provide the alignment mark on the mount surface.